Chemotherapy is the treatment of cancer using chemical substances. Treatments can be either ingested (in pill form) or injected (through intravenous). Chemotherapy is a “systemic” treatment, in that it treats the entire body, since the chemotherapeutic agents are delivered to every cell. The goal of chemotherapy is to prevent the spread of systemic disease, either distant metastasis or further local invasion of the tumour. Often the goal of chemotherapy is not to treat the primary tumour itself, but to prevent its spread throughout the body. Some centres offer “loco-regional” chemotherapy. This is where the chemotherapy is directly inserted into an area affected by tumour – in mesothelioma this would be the peritoneal or pleural cavities. This permits a higher dose of chemotherapy to be directed at the core tumour, but would have less effect on the distant spread of the tumour.
For malignant pleural mesothelioma (MPM) patients in Canada, the most common chemotherapy regimen today is a combination therapy of either raltitrexed or pemetrexed, and Cisplatin. Although manufactured by different pharmaceutical companies, raltitrexed and pemetrexed are both antimetabolites – meaning that they prevent both the growth and survival of cancer cells as well as normal cells. Cisplatin is a platinum containing compound that causes programmed cell death – or apoptosis. It is a long-standing drug that has been used to treat a variety of different cancers for over 30 years. Cisplatin is often associated with side effects, unlike many newer chemotherapy drugs, and as such is administered with an anti-nauseant.
Although both Health Canada and the Food and Drug Administration (FDA) of the US have approved pemetrexed (in combination with Cisplatin) as the first line treatment of patients with MPM whose disease is unresectable, or whose tumours cannot be removed by surgery, some provinces and territories have yet to approve pemetrexed for coverage under their provincial/territorial health plans. As such, only some provinces will pay for pemetrexed while others will only cover raltitrexed (see Medical Insurance and Other Financial Considerations). Cisplatin is currently covered by all provincial and territorial health plans.
For more information on chemotherapy treatments for mesothelioma patients, see: